A ceramic honeycomb structure body 100 has been proposed, which has a configuration in which a plurality of porous honeycomb segments 2 each having a large number of circulation holes 102 are bound one another with an adhesive layer 3 interposed between each two neighboring porous honeycomb segments, as shown in FIG. 1.
However, the ceramic honeycomb structure body 100 has the following problem with the adhesive layers 3.
Specifically, cracks may occur in an interface between one of the honeycomb segments 2 and its corresponding one of the adhesive layers 3, stemming from an environment in which the ceramic honeycomb structure body 100 is in heavy use. In such a case, cracks a at the early stage will develop into splits A, as shown in FIG. 2. This causes reduction in adhesive strength. The ceramic honeycomb structure body 100 has the problem of this type.
In addition, a step of adhering two honeycomb segments 2 and 2, opposite to each other, in the course of manufacturing the ceramic honeycomb structure body 100 is configured: to apply adhesive to one 2b of the two adhesion surfaces 2a and 2b respectively of the two honeycomb segments 2 and 2; thereby to form the adhesive layer 3; thereafter to press the other 2a of the two adhesion surfaces 2a and 2b against the adhesive layer 3; to adhere the two honeycomb segments 2 and 2, as shown in FIG. 3
Incidentally, in this adhering step, moisture movement w from the adhesive layer 3 to the honeycomb segment 2 through the adhesion surface 2b stems from the porosity of the honeycomb segment 2. This moisture movement w forms an interface B with high adhesive strength (a shadowed part in the figure) between the adhesive layer 3 and the adhesion surface 2b. However, this moisture movement w forms an interface b with low adhesive strength between the other surface of the adhesive layer 3 and the adhesion surface 2a, stemming from insufficient moisture. The ceramic honeycomb structure body 100 has another problem that the formation of this interface b with low adhesive strength reduces the overall adhesive strength of the adhesive layer 3.
With these problems taken into consideration, an object of the present invention is to provide a ceramic honeycomb structure body, whose adhesive layer is caused to have an improved adhesive strength by means of precluding cracks from developing into splits and by means of precluding moisture in the adhesive layer from moving to only one of the two opposed honeycomb segments 2, as well as a method of manufacturing the same.